Light-emitting diode devices (LEDs) are extremely useful because they potentially offer lower power consumption and long term durability benefits over the conventional incandescent and fluorescent lamps and frequently provide a functional cost benefit, even when their initial cost is greater than that of conventional lamps. As well known, LEDs are widely used in different fields such as displays, traffic lights, data storage apparatus, communication apparatus, lighting apparatus, and medical apparatus.
The chip size of the light-emitting diode is increasing due to the improvement of the luminous efficiency and the simplification of the circuit design. The input current through the electrode is also increasing in the large-size light-emitting diode chip at a fixed current density. Therefore, the large-size light-emitting diode chip has a plurality of affiliated electrode in the corners or edges in the prior arts like the one shown in FIG. 5. However, the affiliated electrode design may incur the current crowding and the unstable voltage due to the incomplete bonding when using the eutectic bonding technique during packaging. Besides, when the wire bonding technique is applied, the bonding steps and chip packaging complexity are increasing as well.